Evolution of atomic and electronic structures of Cun (n = 2–10) clusters supported on anatase TiO2(1 0 1) surface

Size-Dependent Atomic and Electronic Structures of Small-Sized Nin (n = 2–10) Clusters Supported on the Anatase TiO2(101) Surface: A Density Functional Theory Study

“…Ni 6 -V (Figure 3e) is a planar structure, which is similar to the ground structure of Cu 6 / A(101). 36 The total energy of Ni 6 -V is 0.76 eV higher than that of Ni 6 -I. Such high relative energy between Ni 6 -V and Ni 6 -I indicates that the planar structure is not favored by supported small-sized Ni n clusters.…”

“…Ni 3 -II is a tilted triangle, as shown in Figure 2c, which is similar to the ground state structure of Cu 3 /A(101). 36 The total energy of Ni 3 -II is 0.30 eV higher than that of Ni 3 -I. Therefore, for the supported Ni 3 cluster, a linear structure is favored.…”

“…The atomic structure of the lowest-energy Ni 2 / A(101) is shown in Figure 2a, which is similar to that of Cu 2 / A(101). 36 One Ni atom is located at the bridge site between two O 2c atoms and the other one is located above the neighboring Ti 6c atoms. The Ni−Ni bond length is 2.40 Å, which is longer than that (2.08 Å) in the gas-phased Ni 2 dimer.…”

“…We can also compare these values to those of the TiO 2 -supported Cu n clusters. 36 The absolute values of E int of Ni n /A(101) are obviously larger than those of Cu n /A(101) (4.5−14.5 vs 3.3− 9.3 eV), so the metal−TiO 2 interaction of Ni is actually much stronger than that of Cu, as supposed by Zhou et al 26 The deformation energies of TiO 2 of Ni n /A(101) are also generally larger than those of Cu n /A(101). The stronger metal−TiO 2 interaction of Ni is surely responsible for the severe deformation of the TiO 2 surface.…”

“…The evolutionary algorithm-based USPEX package has shown great success in predicting the most stable structures of various materials. − Therefore, in this work, we performed an extensive search for the most stable structures of various-sized Ni clusters supported on the anatase TiO 2 (101) [denoted as A(101)] surface by using the surface structure prediction module implemented in the USPEX package. The details of our structural search have been described clearly in our previous work. − Briefly, the whole structure model is divided into three regions, that is, the vacuum region, the surface region, and the substrate region. The substrate is simulated by a slab with two TiO 2 layers within a 1 × 3 surface supercell, whose lattice constants are a = 10.38 Å and b = 11.41 Å. Ni cluster structures are generated within the surface region.…”